The suit of necessity would need to be very durable and hence somewhat protective, it's appearance should define that quality (read NOT SPANDEX) but my incarnation of Batman would very rarely if ever be subjected to carefully aimed gunfire. I want to see him nullify gunfire by using stealth and by confusing and disorienting armed opponents. A smoke grenade being the classic methodology.

Besides as has been stated numerous times....no matter how much armor is on Batman's torso, his lower face is always unprotected....making the rationale for extensive armor somewhat frivolous.